1. Field of the Invention
This invention relates generally to battery busbars and more particularly to battery busbars for use on underwater deep submergence batteries.
2. Description of the prior art
The conventional method of rendering deep submergence batteries impermeable to shorting agents is to semi-permanently encapsulate the bussing system within polyurethane. This encapsulated system exhibits several serious disadvantages. The tops of pressure compensated deep submergence batteries utilized to power submersibles have been exposed to battery electrolyte spilled or carried from the cells by vented gas. This carryover phenomena is encouraged by the rapid decompression experienced during the submersibles ascent. This electrolyte establishes electrically conductive paths to the battery's bussing system. Through these paths cell to cell shorts are established and resistance between the battery and seawater ground is often reduced below the minimal acceptable limit for continuing a mission. Even with extensive maintenance these grounds are only temporarily eliminated.
In addition, the polyurethane potted bussing also precluded or made extremely difficult maintenance procedures. It is highly desirable to jumper a single cell or several cells out of a battery circuit during maintenance when the cells state of charge is significantly out of balance with the rest of the battery. With the potted bussing system this procedure requires clipping of large sections of polyurethane and then jumpering the cell. After the charging, the potting must be repoured and allowed to cure. Similarly, when a cell was determined to be in need of replacement it required removing the polyurethane potting, replacing the cell and then repouring the potting and allowing it to cure. In either case, clipping the potting is a time consuming as well as a dangerous task. Repouring the potting and allowing time to cure is a time consuming task. In addition, most of the polyurethane compounds utilized have been identified as cancer suspect agents and therefore must be carefully handled in an approved manner. In short, the utilization of polyurethane insulation makes maintenance and repair extremely difficult and time consuming and does not provide adequate insulation in the presence of battery electrolytes.